This article explains the physiology of lactation – hormonal changes preparing breasts during pregnancy and promoting milk production after delivery, and regulation of milk production according to baby’s demands.
- Lactogenesis I is the stage of maturation of breasts under hormonal control during pregnancy.
- Progesterone, prolactin, and placental lactogen increases the number of alveoli
- Estrogen and growth hormone increases the number of milk ducts
- Lactogenesis II is the stage of copious milk secretion 36-48 hours after birth because of:
- Fall in progesterone levels
- Prolactin hormone
- Early and frequent breastfeeding
- Cortisol and insulin hormone
- Lactogenesis II is called delayed if happens after 72 hours. Delay in lactogenesis II can be prevented by:
- Direct breastfeeding
- Frequent and exclusive breastfeeding
- Initiation of breastfeeding within one hour of birth
- Prolactin is the main hormone for milk production and its levels increase when the baby breastfeeds.
- Metoclopramide and domperidone increase breast milk production by increasing prolactin levels.
- Oxytocin hormone causes ‘let down’ of breast milk.
- Lactogenesis III is the stage of maintenance of milk production.
- Feedback inhibitor of lactation is secreted in alveoli when they are full of milk. It inhibits further milk production.
- Frequent emptying of breasts –> more milk production
- Full breasts –> decreases milk production
Related articles: Breast Anatomy
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